Abstract: A component having an externally engaged actuating member which effects an internal change at what is required to be a closely repeatable position in the movement of the member, e.g. a micro-switch actuated by a push button, is calibrated by progressively moving the actuating member while sensing for the internal change then, when the change occurs, clamping the actuating member (e.g. the push button) and cutting it to length.

Abstract: A key-operated device, for example for controlling access to switch gear or potentially dangerous machinery, has a rotary motion with an axially inserted key but departs from the usual barrel lock construction which is sensitive to foreign matter. Instead it has a faceplate in front of a stationary body with a cylindrical member rotatable in it and having a recess for the key and circumferentially spaced notches in a flange close behind the plate and prevented from direct access through the keyhole by a fixed axially extending wall on the back of the plate but accessible by appropriate lugs on the key when the latter is inserted. The rotatable member is connected through a spindle to a switch, valve or latch or other actuated device.

Abstract: A micro-switch having an actuating mechanism comprising a slide member which is movable longitudinally of itself in the switch casing and engages the electrical switching element, and a pivoted actuator which extends externally of the switch casing and comprises a length of wire which is pivoted in a hole in the switch casing and which has a bent end portion within the casing which is connected to the slide member so that pivoting of the actuator in one particular sense causes the slide member to move longitudinally to operate the switching element. Preferably, said end portion of the wire is connected to the inner end of the slide member by engaging an aperture or recess in the latter. The recess is conveniently a transverse channel formed in the side face of the slide member which is exposed on removal of a switch cover. That portion of the wire projecting from the other side of the casing can be bent through 90.degree.